File : aspects.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- A S P E C T S --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 2010-2016, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This package defines the aspects that are recognized by GNAT in aspect
33 -- specifications. It also contains the subprograms for storing/retrieving
34 -- aspect specifications from the tree. The semantic processing for aspect
35 -- specifications is found in Sem_Ch13.Analyze_Aspect_Specifications.
36
37 ------------------------
38 -- Adding New Aspects --
39 ------------------------
40
41 -- In general, each aspect should have a corresponding pragma, so that the
42 -- newly developed functionality is available for Ada versions < Ada 2012.
43 -- When both are defined, it is convenient to first transform the aspect into
44 -- an equivalent pragma in Sem_Ch13.Analyze_Aspect_Specifications, and then
45 -- analyze the pragma in Sem_Prag.Analyze_Pragma.
46
47 -- To add a new aspect, you need to do the following
48
49 -- 1. Create a name in snames.ads-tmpl
50
51 -- 2. Create a value in type Aspect_Id in this unit
52
53 -- 3. Add a value for the aspect in the global arrays defined in this unit
54
55 -- 4. Add code for the aspect in Sem_Ch13.Analyze_Aspect_Specifications.
56 -- This may involve adding some nodes to the tree to perform additional
57 -- treatments later.
58
59 -- 5. If the semantic analysis of expressions/names in the aspect should not
60 -- occur at the point the aspect is defined, add code in the adequate
61 -- semantic analysis procedure for the aspect. For example, this is the
62 -- case for aspects Pre and Post on subprograms, which are pre-analyzed
63 -- at the end of the declaration list to which the subprogram belongs,
64 -- and fully analyzed (possibly with expansion) during the semantic
65 -- analysis of subprogram bodies.
66
67 with Namet; use Namet;
68 with Snames; use Snames;
69 with Types; use Types;
70
71 package Aspects is
72
73 -- Type defining recognized aspects
74
75 type Aspect_Id is
76 (No_Aspect, -- Dummy entry for no aspect
77 Aspect_Abstract_State, -- GNAT
78 Aspect_Address,
79 Aspect_Alignment,
80 Aspect_Annotate, -- GNAT
81 Aspect_Async_Readers, -- GNAT
82 Aspect_Async_Writers, -- GNAT
83 Aspect_Attach_Handler,
84 Aspect_Bit_Order,
85 Aspect_Component_Size,
86 Aspect_Constant_After_Elaboration, -- GNAT
87 Aspect_Constant_Indexing,
88 Aspect_Contract_Cases, -- GNAT
89 Aspect_Convention,
90 Aspect_CPU,
91 Aspect_Default_Component_Value,
92 Aspect_Default_Initial_Condition, -- GNAT
93 Aspect_Default_Iterator,
94 Aspect_Default_Storage_Pool,
95 Aspect_Default_Value,
96 Aspect_Depends, -- GNAT
97 Aspect_Dimension, -- GNAT
98 Aspect_Dimension_System, -- GNAT
99 Aspect_Dispatching_Domain,
100 Aspect_Dynamic_Predicate,
101 Aspect_Effective_Reads, -- GNAT
102 Aspect_Effective_Writes, -- GNAT
103 Aspect_Extensions_Visible, -- GNAT
104 Aspect_External_Name,
105 Aspect_External_Tag,
106 Aspect_Ghost, -- GNAT
107 Aspect_Global, -- GNAT
108 Aspect_Implicit_Dereference,
109 Aspect_Initial_Condition, -- GNAT
110 Aspect_Initializes, -- GNAT
111 Aspect_Input,
112 Aspect_Interrupt_Priority,
113 Aspect_Invariant, -- GNAT
114 Aspect_Iterator_Element,
115 Aspect_Iterable, -- GNAT
116 Aspect_Link_Name,
117 Aspect_Linker_Section, -- GNAT
118 Aspect_Machine_Radix,
119 Aspect_Object_Size, -- GNAT
120 Aspect_Obsolescent, -- GNAT
121 Aspect_Output,
122 Aspect_Part_Of, -- GNAT
123 Aspect_Post,
124 Aspect_Postcondition,
125 Aspect_Pre,
126 Aspect_Precondition,
127 Aspect_Predicate, -- GNAT
128 Aspect_Predicate_Failure,
129 Aspect_Priority,
130 Aspect_Read,
131 Aspect_Refined_Depends, -- GNAT
132 Aspect_Refined_Global, -- GNAT
133 Aspect_Refined_Post, -- GNAT
134 Aspect_Refined_State, -- GNAT
135 Aspect_Relative_Deadline,
136 Aspect_Scalar_Storage_Order, -- GNAT
137 Aspect_Simple_Storage_Pool, -- GNAT
138 Aspect_Size,
139 Aspect_Small,
140 Aspect_SPARK_Mode, -- GNAT
141 Aspect_Static_Predicate,
142 Aspect_Storage_Pool,
143 Aspect_Storage_Size,
144 Aspect_Stream_Size,
145 Aspect_Suppress,
146 Aspect_Synchronization,
147 Aspect_Test_Case, -- GNAT
148 Aspect_Type_Invariant,
149 Aspect_Unimplemented, -- GNAT
150 Aspect_Unsuppress,
151 Aspect_Value_Size, -- GNAT
152 Aspect_Variable_Indexing,
153 Aspect_Volatile_Function, -- GNAT
154 Aspect_Warnings, -- GNAT
155 Aspect_Write,
156
157 -- The following aspects correspond to library unit pragmas
158
159 Aspect_All_Calls_Remote,
160 Aspect_Elaborate_Body,
161 Aspect_No_Elaboration_Code_All, -- GNAT
162 Aspect_Preelaborate,
163 Aspect_Pure,
164 Aspect_Remote_Call_Interface,
165 Aspect_Remote_Types,
166 Aspect_Shared_Passive,
167 Aspect_Universal_Data, -- GNAT
168
169 -- Remaining aspects have a static boolean value that turns the aspect
170 -- on or off. They all correspond to pragmas, but are only converted to
171 -- the pragmas where the value is True. A value of False normally means
172 -- that the aspect is ignored, except in the case of derived types where
173 -- the aspect value is inherited from the parent, in which case, we do
174 -- not allow False if we inherit a True value from the parent.
175
176 Aspect_Asynchronous,
177 Aspect_Atomic,
178 Aspect_Atomic_Components,
179 Aspect_Disable_Controlled, -- GNAT
180 Aspect_Discard_Names,
181 Aspect_Export,
182 Aspect_Favor_Top_Level, -- GNAT
183 Aspect_Independent,
184 Aspect_Independent_Components,
185 Aspect_Import,
186 Aspect_Inline,
187 Aspect_Inline_Always, -- GNAT
188 Aspect_Interrupt_Handler,
189 Aspect_Lock_Free, -- GNAT
190 Aspect_No_Return,
191 Aspect_No_Tagged_Streams, -- GNAT
192 Aspect_Pack,
193 Aspect_Persistent_BSS, -- GNAT
194 Aspect_Preelaborable_Initialization,
195 Aspect_Pure_Function, -- GNAT
196 Aspect_Remote_Access_Type, -- GNAT
197 Aspect_Shared, -- GNAT (equivalent to Atomic)
198 Aspect_Simple_Storage_Pool_Type, -- GNAT
199 Aspect_Suppress_Debug_Info, -- GNAT
200 Aspect_Suppress_Initialization, -- GNAT
201 Aspect_Thread_Local_Storage, -- GNAT
202 Aspect_Unchecked_Union,
203 Aspect_Universal_Aliasing, -- GNAT
204 Aspect_Unmodified, -- GNAT
205 Aspect_Unreferenced, -- GNAT
206 Aspect_Unreferenced_Objects, -- GNAT
207 Aspect_Volatile,
208 Aspect_Volatile_Components,
209 Aspect_Volatile_Full_Access); -- GNAT
210
211 subtype Aspect_Id_Exclude_No_Aspect is
212 Aspect_Id range Aspect_Id'Succ (No_Aspect) .. Aspect_Id'Last;
213 -- Aspect_Id's excluding No_Aspect
214
215 -- The following array indicates aspects that accept 'Class
216
217 Class_Aspect_OK : constant array (Aspect_Id) of Boolean :=
218 (Aspect_Input => True,
219 Aspect_Invariant => True,
220 Aspect_Output => True,
221 Aspect_Pre => True,
222 Aspect_Predicate => True,
223 Aspect_Post => True,
224 Aspect_Read => True,
225 Aspect_Write => True,
226 Aspect_Type_Invariant => True,
227 others => False);
228
229 -- The following array identifies all implementation defined aspects
230
231 Implementation_Defined_Aspect : constant array (Aspect_Id) of Boolean :=
232 (Aspect_Abstract_State => True,
233 Aspect_Annotate => True,
234 Aspect_Async_Readers => True,
235 Aspect_Async_Writers => True,
236 Aspect_Constant_After_Elaboration => True,
237 Aspect_Contract_Cases => True,
238 Aspect_Depends => True,
239 Aspect_Dimension => True,
240 Aspect_Dimension_System => True,
241 Aspect_Effective_Reads => True,
242 Aspect_Effective_Writes => True,
243 Aspect_Extensions_Visible => True,
244 Aspect_Favor_Top_Level => True,
245 Aspect_Ghost => True,
246 Aspect_Global => True,
247 Aspect_Inline_Always => True,
248 Aspect_Invariant => True,
249 Aspect_Lock_Free => True,
250 Aspect_Object_Size => True,
251 Aspect_Persistent_BSS => True,
252 Aspect_Predicate => True,
253 Aspect_Pure_Function => True,
254 Aspect_Remote_Access_Type => True,
255 Aspect_Scalar_Storage_Order => True,
256 Aspect_Shared => True,
257 Aspect_Simple_Storage_Pool => True,
258 Aspect_Simple_Storage_Pool_Type => True,
259 Aspect_Suppress_Debug_Info => True,
260 Aspect_Suppress_Initialization => True,
261 Aspect_Thread_Local_Storage => True,
262 Aspect_Test_Case => True,
263 Aspect_Universal_Aliasing => True,
264 Aspect_Universal_Data => True,
265 Aspect_Unmodified => True,
266 Aspect_Unreferenced => True,
267 Aspect_Unreferenced_Objects => True,
268 Aspect_Value_Size => True,
269 Aspect_Volatile_Function => True,
270 Aspect_Warnings => True,
271 others => False);
272
273 -- The following array indicates aspects for which multiple occurrences of
274 -- the same aspect attached to the same declaration are allowed.
275
276 No_Duplicates_Allowed : constant array (Aspect_Id) of Boolean :=
277 (Aspect_Annotate => False,
278 Aspect_Test_Case => False,
279 others => True);
280
281 -- The following subtype defines aspects corresponding to library unit
282 -- pragmas, these can only validly appear as aspects for library units,
283 -- and result in a corresponding pragma being inserted immediately after
284 -- the occurrence of the aspect.
285
286 subtype Library_Unit_Aspects is
287 Aspect_Id range Aspect_All_Calls_Remote .. Aspect_Universal_Data;
288
289 -- The following subtype defines aspects accepting an optional static
290 -- boolean parameter indicating if the aspect should be active or
291 -- cancelling. If the parameter is missing the effective value is True,
292 -- enabling the aspect. If the parameter is present it must be a static
293 -- expression of type Standard.Boolean. If the value is True, then the
294 -- aspect is enabled. If it is False, the aspect is disabled.
295
296 subtype Boolean_Aspects is
297 Aspect_Id range Aspect_Asynchronous .. Aspect_Id'Last;
298
299 subtype Pre_Post_Aspects is
300 Aspect_Id range Aspect_Post .. Aspect_Precondition;
301
302 -- The following type is used for indicating allowed expression forms
303
304 type Aspect_Expression is
305 (Expression, -- Required expression
306 Name, -- Required name
307 Optional_Expression, -- Optional boolean expression
308 Optional_Name); -- Optional name
309
310 -- The following array indicates what argument type is required
311
312 Aspect_Argument : constant array (Aspect_Id) of Aspect_Expression :=
313 (No_Aspect => Optional_Expression,
314 Aspect_Abstract_State => Expression,
315 Aspect_Address => Expression,
316 Aspect_Alignment => Expression,
317 Aspect_Annotate => Expression,
318 Aspect_Async_Readers => Optional_Expression,
319 Aspect_Async_Writers => Optional_Expression,
320 Aspect_Attach_Handler => Expression,
321 Aspect_Bit_Order => Expression,
322 Aspect_Component_Size => Expression,
323 Aspect_Constant_After_Elaboration => Optional_Expression,
324 Aspect_Constant_Indexing => Name,
325 Aspect_Contract_Cases => Expression,
326 Aspect_Convention => Name,
327 Aspect_CPU => Expression,
328 Aspect_Default_Component_Value => Expression,
329 Aspect_Default_Initial_Condition => Optional_Expression,
330 Aspect_Default_Iterator => Name,
331 Aspect_Default_Storage_Pool => Expression,
332 Aspect_Default_Value => Expression,
333 Aspect_Depends => Expression,
334 Aspect_Dimension => Expression,
335 Aspect_Dimension_System => Expression,
336 Aspect_Dispatching_Domain => Expression,
337 Aspect_Dynamic_Predicate => Expression,
338 Aspect_Effective_Reads => Optional_Expression,
339 Aspect_Effective_Writes => Optional_Expression,
340 Aspect_Extensions_Visible => Optional_Expression,
341 Aspect_External_Name => Expression,
342 Aspect_External_Tag => Expression,
343 Aspect_Ghost => Optional_Expression,
344 Aspect_Global => Expression,
345 Aspect_Implicit_Dereference => Name,
346 Aspect_Initial_Condition => Expression,
347 Aspect_Initializes => Expression,
348 Aspect_Input => Name,
349 Aspect_Interrupt_Priority => Expression,
350 Aspect_Invariant => Expression,
351 Aspect_Iterable => Expression,
352 Aspect_Iterator_Element => Name,
353 Aspect_Link_Name => Expression,
354 Aspect_Linker_Section => Expression,
355 Aspect_Machine_Radix => Expression,
356 Aspect_Object_Size => Expression,
357 Aspect_Obsolescent => Optional_Expression,
358 Aspect_Output => Name,
359 Aspect_Part_Of => Expression,
360 Aspect_Post => Expression,
361 Aspect_Postcondition => Expression,
362 Aspect_Pre => Expression,
363 Aspect_Precondition => Expression,
364 Aspect_Predicate => Expression,
365 Aspect_Predicate_Failure => Expression,
366 Aspect_Priority => Expression,
367 Aspect_Read => Name,
368 Aspect_Refined_Depends => Expression,
369 Aspect_Refined_Global => Expression,
370 Aspect_Refined_Post => Expression,
371 Aspect_Refined_State => Expression,
372 Aspect_Relative_Deadline => Expression,
373 Aspect_Scalar_Storage_Order => Expression,
374 Aspect_Simple_Storage_Pool => Name,
375 Aspect_Size => Expression,
376 Aspect_Small => Expression,
377 Aspect_SPARK_Mode => Optional_Name,
378 Aspect_Static_Predicate => Expression,
379 Aspect_Storage_Pool => Name,
380 Aspect_Storage_Size => Expression,
381 Aspect_Stream_Size => Expression,
382 Aspect_Suppress => Name,
383 Aspect_Synchronization => Name,
384 Aspect_Test_Case => Expression,
385 Aspect_Type_Invariant => Expression,
386 Aspect_Unimplemented => Optional_Expression,
387 Aspect_Unsuppress => Name,
388 Aspect_Value_Size => Expression,
389 Aspect_Variable_Indexing => Name,
390 Aspect_Volatile_Function => Optional_Expression,
391 Aspect_Warnings => Name,
392 Aspect_Write => Name,
393
394 Boolean_Aspects => Optional_Expression,
395 Library_Unit_Aspects => Optional_Expression);
396
397 -----------------------------------------
398 -- Table Linking Names and Aspect_Id's --
399 -----------------------------------------
400
401 -- Table linking aspect names and id's
402
403 Aspect_Names : constant array (Aspect_Id) of Name_Id :=
404 (No_Aspect => No_Name,
405 Aspect_Abstract_State => Name_Abstract_State,
406 Aspect_Address => Name_Address,
407 Aspect_Alignment => Name_Alignment,
408 Aspect_All_Calls_Remote => Name_All_Calls_Remote,
409 Aspect_Annotate => Name_Annotate,
410 Aspect_Async_Readers => Name_Async_Readers,
411 Aspect_Async_Writers => Name_Async_Writers,
412 Aspect_Asynchronous => Name_Asynchronous,
413 Aspect_Atomic => Name_Atomic,
414 Aspect_Atomic_Components => Name_Atomic_Components,
415 Aspect_Attach_Handler => Name_Attach_Handler,
416 Aspect_Bit_Order => Name_Bit_Order,
417 Aspect_Component_Size => Name_Component_Size,
418 Aspect_Constant_After_Elaboration => Name_Constant_After_Elaboration,
419 Aspect_Constant_Indexing => Name_Constant_Indexing,
420 Aspect_Contract_Cases => Name_Contract_Cases,
421 Aspect_Convention => Name_Convention,
422 Aspect_CPU => Name_CPU,
423 Aspect_Default_Component_Value => Name_Default_Component_Value,
424 Aspect_Default_Initial_Condition => Name_Default_Initial_Condition,
425 Aspect_Default_Iterator => Name_Default_Iterator,
426 Aspect_Default_Storage_Pool => Name_Default_Storage_Pool,
427 Aspect_Default_Value => Name_Default_Value,
428 Aspect_Depends => Name_Depends,
429 Aspect_Dimension => Name_Dimension,
430 Aspect_Dimension_System => Name_Dimension_System,
431 Aspect_Disable_Controlled => Name_Disable_Controlled,
432 Aspect_Discard_Names => Name_Discard_Names,
433 Aspect_Dispatching_Domain => Name_Dispatching_Domain,
434 Aspect_Dynamic_Predicate => Name_Dynamic_Predicate,
435 Aspect_Effective_Reads => Name_Effective_Reads,
436 Aspect_Effective_Writes => Name_Effective_Writes,
437 Aspect_Elaborate_Body => Name_Elaborate_Body,
438 Aspect_Export => Name_Export,
439 Aspect_Extensions_Visible => Name_Extensions_Visible,
440 Aspect_External_Name => Name_External_Name,
441 Aspect_External_Tag => Name_External_Tag,
442 Aspect_Favor_Top_Level => Name_Favor_Top_Level,
443 Aspect_Ghost => Name_Ghost,
444 Aspect_Global => Name_Global,
445 Aspect_Implicit_Dereference => Name_Implicit_Dereference,
446 Aspect_Import => Name_Import,
447 Aspect_Independent => Name_Independent,
448 Aspect_Independent_Components => Name_Independent_Components,
449 Aspect_Inline => Name_Inline,
450 Aspect_Inline_Always => Name_Inline_Always,
451 Aspect_Initial_Condition => Name_Initial_Condition,
452 Aspect_Initializes => Name_Initializes,
453 Aspect_Input => Name_Input,
454 Aspect_Interrupt_Handler => Name_Interrupt_Handler,
455 Aspect_Interrupt_Priority => Name_Interrupt_Priority,
456 Aspect_Invariant => Name_Invariant,
457 Aspect_Iterator_Element => Name_Iterator_Element,
458 Aspect_Iterable => Name_Iterable,
459 Aspect_Link_Name => Name_Link_Name,
460 Aspect_Linker_Section => Name_Linker_Section,
461 Aspect_Lock_Free => Name_Lock_Free,
462 Aspect_Machine_Radix => Name_Machine_Radix,
463 Aspect_No_Elaboration_Code_All => Name_No_Elaboration_Code_All,
464 Aspect_No_Return => Name_No_Return,
465 Aspect_No_Tagged_Streams => Name_No_Tagged_Streams,
466 Aspect_Object_Size => Name_Object_Size,
467 Aspect_Obsolescent => Name_Obsolescent,
468 Aspect_Output => Name_Output,
469 Aspect_Pack => Name_Pack,
470 Aspect_Part_Of => Name_Part_Of,
471 Aspect_Persistent_BSS => Name_Persistent_BSS,
472 Aspect_Post => Name_Post,
473 Aspect_Postcondition => Name_Postcondition,
474 Aspect_Pre => Name_Pre,
475 Aspect_Precondition => Name_Precondition,
476 Aspect_Predicate => Name_Predicate,
477 Aspect_Predicate_Failure => Name_Predicate_Failure,
478 Aspect_Preelaborable_Initialization => Name_Preelaborable_Initialization,
479 Aspect_Preelaborate => Name_Preelaborate,
480 Aspect_Priority => Name_Priority,
481 Aspect_Pure => Name_Pure,
482 Aspect_Pure_Function => Name_Pure_Function,
483 Aspect_Read => Name_Read,
484 Aspect_Refined_Depends => Name_Refined_Depends,
485 Aspect_Refined_Global => Name_Refined_Global,
486 Aspect_Refined_Post => Name_Refined_Post,
487 Aspect_Refined_State => Name_Refined_State,
488 Aspect_Relative_Deadline => Name_Relative_Deadline,
489 Aspect_Remote_Access_Type => Name_Remote_Access_Type,
490 Aspect_Remote_Call_Interface => Name_Remote_Call_Interface,
491 Aspect_Remote_Types => Name_Remote_Types,
492 Aspect_Scalar_Storage_Order => Name_Scalar_Storage_Order,
493 Aspect_Shared => Name_Shared,
494 Aspect_Shared_Passive => Name_Shared_Passive,
495 Aspect_Simple_Storage_Pool => Name_Simple_Storage_Pool,
496 Aspect_Simple_Storage_Pool_Type => Name_Simple_Storage_Pool_Type,
497 Aspect_Size => Name_Size,
498 Aspect_Small => Name_Small,
499 Aspect_SPARK_Mode => Name_SPARK_Mode,
500 Aspect_Static_Predicate => Name_Static_Predicate,
501 Aspect_Storage_Pool => Name_Storage_Pool,
502 Aspect_Storage_Size => Name_Storage_Size,
503 Aspect_Stream_Size => Name_Stream_Size,
504 Aspect_Suppress => Name_Suppress,
505 Aspect_Suppress_Debug_Info => Name_Suppress_Debug_Info,
506 Aspect_Suppress_Initialization => Name_Suppress_Initialization,
507 Aspect_Thread_Local_Storage => Name_Thread_Local_Storage,
508 Aspect_Synchronization => Name_Synchronization,
509 Aspect_Test_Case => Name_Test_Case,
510 Aspect_Type_Invariant => Name_Type_Invariant,
511 Aspect_Unchecked_Union => Name_Unchecked_Union,
512 Aspect_Unimplemented => Name_Unimplemented,
513 Aspect_Universal_Aliasing => Name_Universal_Aliasing,
514 Aspect_Universal_Data => Name_Universal_Data,
515 Aspect_Unmodified => Name_Unmodified,
516 Aspect_Unreferenced => Name_Unreferenced,
517 Aspect_Unreferenced_Objects => Name_Unreferenced_Objects,
518 Aspect_Unsuppress => Name_Unsuppress,
519 Aspect_Value_Size => Name_Value_Size,
520 Aspect_Variable_Indexing => Name_Variable_Indexing,
521 Aspect_Volatile => Name_Volatile,
522 Aspect_Volatile_Components => Name_Volatile_Components,
523 Aspect_Volatile_Full_Access => Name_Volatile_Full_Access,
524 Aspect_Volatile_Function => Name_Volatile_Function,
525 Aspect_Warnings => Name_Warnings,
526 Aspect_Write => Name_Write);
527
528 function Get_Aspect_Id (Name : Name_Id) return Aspect_Id;
529 pragma Inline (Get_Aspect_Id);
530 -- Given a name Nam, returns the corresponding aspect id value. If the name
531 -- does not match any aspect, then No_Aspect is returned as the result.
532
533 function Get_Aspect_Id (Aspect : Node_Id) return Aspect_Id;
534 pragma Inline (Get_Aspect_Id);
535 -- Given an aspect specification, return the corresponding aspect_id value.
536 -- If the name does not match any aspect, return No_Aspect.
537
538 ------------------------------------
539 -- Delaying Evaluation of Aspects --
540 ------------------------------------
541
542 -- The RM requires that all language defined aspects taking an expression
543 -- delay evaluation of the expression till the freeze point of the entity
544 -- to which the aspect applies. This allows forward references, and is of
545 -- use for example in connection with preconditions and postconditions
546 -- where the requirement of making all references in contracts to local
547 -- functions be backwards references would be onerous.
548
549 -- For consistency, even attributes like Size are delayed, so we can do:
550
551 -- type A is range 1 .. 10
552 -- with Size => Not_Defined_Yet;
553 -- ..
554 -- Not_Defined_Yet : constant := 64;
555
556 -- Resulting in A having a size of 64, which gets set when A is frozen.
557 -- Furthermore, we can have a situation like
558
559 -- type A is range 1 .. 10
560 -- with Size => Not_Defined_Yet;
561 -- ..
562 -- type B is new A;
563 -- ..
564 -- Not_Defined_Yet : constant := 64;
565
566 -- where the Size of A is considered to have been previously specified at
567 -- the point of derivation, even though the actual value of the size is
568 -- not known yet, and in this example B inherits the size value of 64.
569
570 -- Our normal implementation model (prior to Ada 2012) was simply to copy
571 -- inheritable attributes at the point of derivation. Then any subsequent
572 -- representation items apply either to the parent type, not affecting the
573 -- derived type, or to the derived type, not affecting the parent type.
574
575 -- To deal with the delayed aspect case, we use two flags. The first is
576 -- set on the parent type if it has delayed representation aspects. This
577 -- flag Has_Delayed_Rep_Aspects indicates that if we derive from this type
578 -- we have to worry about making sure we inherit any delayed aspects. The
579 -- second flag is set on a derived type: May_Have_Inherited_Rep_Aspects
580 -- is set if the parent type has Has_Delayed_Rep_Aspects set.
581
582 -- When we freeze a derived type, if the May_Have_Inherited_Rep_Aspects
583 -- flag is set, then we call Freeze.Inherit_Delayed_Rep_Aspects when
584 -- the derived type is frozen, which deals with the necessary copying of
585 -- information from the parent type, which must be frozen at that point
586 -- (since freezing the derived type first freezes the parent type).
587
588 -- SPARK 2014 aspects do not follow the general delay mechanism as they
589 -- act as annotations and cannot modify the attributes of their related
590 -- constructs. To handle forward references in such aspects, the compiler
591 -- delays the analysis of their respective pragmas by collecting them in
592 -- N_Contract nodes. The pragmas are then analyzed at the end of the
593 -- declarative region containing the related construct. For details,
594 -- see routines Analyze_xxx_In_Decl_Part.
595
596 -- The following shows which aspects are delayed. There are three cases:
597
598 type Delay_Type is
599 (Always_Delay,
600 -- This aspect is not a representation aspect that can be inherited and
601 -- is always delayed, as required by the language definition.
602
603 Never_Delay,
604 -- There are two cases. There are language defined aspects like
605 -- Convention where the "expression" is simply an uninterpreted
606 -- identifier, and there is no issue of evaluating it and thus no
607 -- issue of delaying the evaluation. The second case is implementation
608 -- defined aspects where we have decided that we don't want to allow
609 -- delays (and for our own aspects we can do what we like).
610
611 Rep_Aspect);
612 -- These are the cases of representation aspects that are in general
613 -- delayed, and where there is a potential issue of derived types that
614 -- inherit delayed representation values.
615
616 -- Note: even if this table indicates that an aspect is delayed, we never
617 -- delay Boolean aspects that have a missing expression (taken as True),
618 -- or expressions for delayed rep items that consist of an integer literal
619 -- (most cases of Size etc. in practice), since in these cases we know we
620 -- can get the value of the expression without delay. Note that we still
621 -- need to delay Boolean aspects that are specifically set to True:
622
623 -- type R is array (0 .. 31) of Boolean
624 -- with Pack => True;
625 -- True : constant Boolean := False;
626
627 -- This is nonsense, but we need to make it work and result in R not
628 -- being packed, and if we have something like:
629
630 -- type R is array (0 .. 31) of Boolean
631 -- with Pack => True;
632 -- RR : R;
633 -- True : constant Boolean := False;
634
635 -- This is illegal because the visibility of True changes after the freeze
636 -- point, which is not allowed, and we need the delay mechanism to properly
637 -- diagnose this error.
638
639 Aspect_Delay : constant array (Aspect_Id) of Delay_Type :=
640 (No_Aspect => Always_Delay,
641 Aspect_Address => Always_Delay,
642 Aspect_All_Calls_Remote => Always_Delay,
643 Aspect_Asynchronous => Always_Delay,
644 Aspect_Attach_Handler => Always_Delay,
645 Aspect_Constant_Indexing => Always_Delay,
646 Aspect_CPU => Always_Delay,
647 Aspect_Default_Iterator => Always_Delay,
648 Aspect_Default_Storage_Pool => Always_Delay,
649 Aspect_Default_Value => Always_Delay,
650 Aspect_Default_Component_Value => Always_Delay,
651 Aspect_Discard_Names => Always_Delay,
652 Aspect_Dispatching_Domain => Always_Delay,
653 Aspect_Dynamic_Predicate => Always_Delay,
654 Aspect_Elaborate_Body => Always_Delay,
655 Aspect_External_Name => Always_Delay,
656 Aspect_External_Tag => Always_Delay,
657 Aspect_Favor_Top_Level => Always_Delay,
658 Aspect_Implicit_Dereference => Always_Delay,
659 Aspect_Independent => Always_Delay,
660 Aspect_Independent_Components => Always_Delay,
661 Aspect_Inline => Always_Delay,
662 Aspect_Inline_Always => Always_Delay,
663 Aspect_Input => Always_Delay,
664 Aspect_Interrupt_Handler => Always_Delay,
665 Aspect_Interrupt_Priority => Always_Delay,
666 Aspect_Invariant => Always_Delay,
667 Aspect_Iterable => Always_Delay,
668 Aspect_Iterator_Element => Always_Delay,
669 Aspect_Link_Name => Always_Delay,
670 Aspect_Linker_Section => Always_Delay,
671 Aspect_Lock_Free => Always_Delay,
672 Aspect_No_Return => Always_Delay,
673 Aspect_Output => Always_Delay,
674 Aspect_Persistent_BSS => Always_Delay,
675 Aspect_Post => Always_Delay,
676 Aspect_Postcondition => Always_Delay,
677 Aspect_Pre => Always_Delay,
678 Aspect_Precondition => Always_Delay,
679 Aspect_Predicate => Always_Delay,
680 Aspect_Predicate_Failure => Always_Delay,
681 Aspect_Preelaborable_Initialization => Always_Delay,
682 Aspect_Preelaborate => Always_Delay,
683 Aspect_Priority => Always_Delay,
684 Aspect_Pure => Always_Delay,
685 Aspect_Pure_Function => Always_Delay,
686 Aspect_Read => Always_Delay,
687 Aspect_Relative_Deadline => Always_Delay,
688 Aspect_Remote_Access_Type => Always_Delay,
689 Aspect_Remote_Call_Interface => Always_Delay,
690 Aspect_Remote_Types => Always_Delay,
691 Aspect_Shared => Always_Delay,
692 Aspect_Shared_Passive => Always_Delay,
693 Aspect_Simple_Storage_Pool => Always_Delay,
694 Aspect_Simple_Storage_Pool_Type => Always_Delay,
695 Aspect_Static_Predicate => Always_Delay,
696 Aspect_Storage_Pool => Always_Delay,
697 Aspect_Stream_Size => Always_Delay,
698 Aspect_Suppress => Always_Delay,
699 Aspect_Suppress_Debug_Info => Always_Delay,
700 Aspect_Suppress_Initialization => Always_Delay,
701 Aspect_Thread_Local_Storage => Always_Delay,
702 Aspect_Type_Invariant => Always_Delay,
703 Aspect_Unchecked_Union => Always_Delay,
704 Aspect_Universal_Aliasing => Always_Delay,
705 Aspect_Universal_Data => Always_Delay,
706 Aspect_Unmodified => Always_Delay,
707 Aspect_Unreferenced => Always_Delay,
708 Aspect_Unreferenced_Objects => Always_Delay,
709 Aspect_Unsuppress => Always_Delay,
710 Aspect_Variable_Indexing => Always_Delay,
711 Aspect_Write => Always_Delay,
712
713 Aspect_Abstract_State => Never_Delay,
714 Aspect_Annotate => Never_Delay,
715 Aspect_Async_Readers => Never_Delay,
716 Aspect_Async_Writers => Never_Delay,
717 Aspect_Constant_After_Elaboration => Never_Delay,
718 Aspect_Contract_Cases => Never_Delay,
719 Aspect_Convention => Never_Delay,
720 Aspect_Default_Initial_Condition => Never_Delay,
721 Aspect_Depends => Never_Delay,
722 Aspect_Dimension => Never_Delay,
723 Aspect_Dimension_System => Never_Delay,
724 Aspect_Disable_Controlled => Never_Delay,
725 Aspect_Effective_Reads => Never_Delay,
726 Aspect_Effective_Writes => Never_Delay,
727 Aspect_Export => Never_Delay,
728 Aspect_Extensions_Visible => Never_Delay,
729 Aspect_Ghost => Never_Delay,
730 Aspect_Global => Never_Delay,
731 Aspect_Import => Never_Delay,
732 Aspect_Initial_Condition => Never_Delay,
733 Aspect_Initializes => Never_Delay,
734 Aspect_No_Elaboration_Code_All => Never_Delay,
735 Aspect_No_Tagged_Streams => Never_Delay,
736 Aspect_Obsolescent => Never_Delay,
737 Aspect_Part_Of => Never_Delay,
738 Aspect_Refined_Depends => Never_Delay,
739 Aspect_Refined_Global => Never_Delay,
740 Aspect_Refined_Post => Never_Delay,
741 Aspect_Refined_State => Never_Delay,
742 Aspect_SPARK_Mode => Never_Delay,
743 Aspect_Synchronization => Never_Delay,
744 Aspect_Test_Case => Never_Delay,
745 Aspect_Unimplemented => Never_Delay,
746 Aspect_Volatile_Function => Never_Delay,
747 Aspect_Warnings => Never_Delay,
748
749 Aspect_Alignment => Rep_Aspect,
750 Aspect_Atomic => Rep_Aspect,
751 Aspect_Atomic_Components => Rep_Aspect,
752 Aspect_Bit_Order => Rep_Aspect,
753 Aspect_Component_Size => Rep_Aspect,
754 Aspect_Machine_Radix => Rep_Aspect,
755 Aspect_Object_Size => Rep_Aspect,
756 Aspect_Pack => Rep_Aspect,
757 Aspect_Scalar_Storage_Order => Rep_Aspect,
758 Aspect_Size => Rep_Aspect,
759 Aspect_Small => Rep_Aspect,
760 Aspect_Storage_Size => Rep_Aspect,
761 Aspect_Value_Size => Rep_Aspect,
762 Aspect_Volatile => Rep_Aspect,
763 Aspect_Volatile_Components => Rep_Aspect,
764 Aspect_Volatile_Full_Access => Rep_Aspect);
765
766 ------------------------------------------------
767 -- Handling of Aspect Specifications on Stubs --
768 ------------------------------------------------
769
770 -- Aspects that appear on the following stub nodes
771
772 -- N_Package_Body_Stub
773 -- N_Protected_Body_Stub
774 -- N_Subprogram_Body_Stub
775 -- N_Task_Body_Stub
776
777 -- are treated as if they apply to the corresponding proper body. Their
778 -- analysis is postponed until the analysis of the proper body takes place
779 -- (see Analyze_Proper_Body). The delay is required because the analysis
780 -- may generate extra code which would be harder to relocate to the body.
781 -- If the proper body is present, the aspect specifications are relocated
782 -- to the corresponding body node:
783
784 -- N_Package_Body
785 -- N_Protected_Body
786 -- N_Subprogram_Body
787 -- N_Task_Body
788
789 -- The subsequent analysis takes care of the aspect-to-pragma conversions
790 -- and verification of pragma legality. In the case where the proper body
791 -- is not available, the aspect specifications are analyzed on the spot
792 -- (see Analyze_Proper_Body) to catch potential errors.
793
794 -- The following table lists all aspects that can apply to a subprogram
795 -- body [stub]. For instance, the following example is legal:
796
797 -- package P with SPARK_Mode ...;
798 -- package body P with SPARK_Mode is ...;
799
800 -- The table should be synchronized with Pragma_On_Body_Or_Stub_OK in unit
801 -- Sem_Prag.
802
803 Aspect_On_Body_Or_Stub_OK : constant array (Aspect_Id) of Boolean :=
804 (Aspect_Refined_Depends => True,
805 Aspect_Refined_Global => True,
806 Aspect_Refined_Post => True,
807 Aspect_SPARK_Mode => True,
808 Aspect_Warnings => True,
809 others => False);
810
811 -------------------------------------------------------------------
812 -- Handling of Aspects Specifications on Single Concurrent Types --
813 -------------------------------------------------------------------
814
815 -- Certain aspects that appear on the following nodes
816
817 -- N_Single_Protected_Declaration
818 -- N_Single_Task_Declaration
819
820 -- are treated as if they apply to the anonymous object produced by the
821 -- analysis of a single concurrent type. The following table lists all
822 -- aspects that should apply to the anonymous object. The table should
823 -- be synchronized with Pragma_On_Anonymous_Object_OK in unit Sem_Prag.
824
825 Aspect_On_Anonymous_Object_OK : constant array (Aspect_Id) of Boolean :=
826 (Aspect_Depends => True,
827 Aspect_Global => True,
828 Aspect_Part_Of => True,
829 others => False);
830
831 ---------------------------------------------------
832 -- Handling of Aspect Specifications in the Tree --
833 ---------------------------------------------------
834
835 -- Several kinds of declaration node permit aspect specifications in Ada
836 -- 2012 mode. If there was room in all the corresponding declaration nodes,
837 -- we could just have a field Aspect_Specifications pointing to a list of
838 -- nodes for the aspects (N_Aspect_Specification nodes). But there isn't
839 -- room, so we adopt a different approach.
840
841 -- The following subprograms provide access to a specialized interface
842 -- implemented internally with a hash table in the body, that provides
843 -- access to aspect specifications.
844
845 function Aspect_Specifications (N : Node_Id) return List_Id;
846 -- Given a node N, returns the list of N_Aspect_Specification nodes that
847 -- are attached to this declaration node. If the node is in the class of
848 -- declaration nodes that permit aspect specifications, as defined by the
849 -- predicate above, and if their Has_Aspects flag is set to True, then this
850 -- will always be a non-empty list. If this flag is set to False, then
851 -- No_List is returned. Normally, the only nodes that have Has_Aspects set
852 -- True are the nodes for which Permits_Aspect_Specifications would return
853 -- True (i.e. the declaration nodes defined in the RM as permitting the
854 -- presence of Aspect_Specifications). However, it is possible for the
855 -- flag Has_Aspects to be set on other nodes as a result of Rewrite and
856 -- Replace calls, and this function may be used to retrieve the aspect
857 -- specifications for the original rewritten node in such cases.
858
859 function Aspects_On_Body_Or_Stub_OK (N : Node_Id) return Boolean;
860 -- N denotes a body [stub] with aspects. Determine whether all aspects of N
861 -- are allowed to appear on a body [stub].
862
863 procedure Exchange_Aspects (N1 : Node_Id; N2 : Node_Id);
864 -- Exchange the aspect specifications of two nodes. If either node lacks an
865 -- aspect specification list, the routine has no effect. It is assumed that
866 -- both nodes can support aspects.
867
868 function Find_Aspect (Id : Entity_Id; A : Aspect_Id) return Node_Id;
869 -- Find the aspect specification of aspect A associated with entity I.
870 -- Return Empty if Id does not have the requested aspect.
871
872 function Find_Value_Of_Aspect
873 (Id : Entity_Id;
874 A : Aspect_Id) return Node_Id;
875 -- Find the value of aspect A associated with entity Id. Return Empty if
876 -- Id does not have the requested aspect.
877
878 function Has_Aspect (Id : Entity_Id; A : Aspect_Id) return Boolean;
879 -- Determine whether entity Id has aspect A
880
881 procedure Move_Aspects (From : Node_Id; To : Node_Id);
882 -- Relocate the aspect specifications of node From to node To. On entry it
883 -- is assumed that To does not have aspect specifications. If From has no
884 -- aspects, the routine has no effect.
885
886 procedure Move_Or_Merge_Aspects (From : Node_Id; To : Node_Id);
887 -- Relocate the aspect specifications of node From to node To. If To has
888 -- aspects, the aspects of From are appended to the aspects of To. If From
889 -- has no aspects, the routine has no effect. Special behavior:
890 -- * When node From denotes a subprogram body stub without a previous
891 -- declaration, the only aspects relocated to node To are those found
892 -- in table Aspect_On_Body_Or_Stub_OK.
893 -- * When node From denotes a single synchronized type declaration, the
894 -- only aspects relocated to node To are those found in table
895 -- Aspect_On_Anonymous_Object_OK.
896
897 function Permits_Aspect_Specifications (N : Node_Id) return Boolean;
898 -- Returns True if the node N is a declaration node that permits aspect
899 -- specifications in the grammar. It is possible for other nodes to have
900 -- aspect specifications as a result of Rewrite or Replace calls.
901
902 procedure Remove_Aspects (N : Node_Id);
903 -- Delete the aspect specifications associated with node N. If the node has
904 -- no aspects, the routine has no effect.
905
906 function Same_Aspect (A1 : Aspect_Id; A2 : Aspect_Id) return Boolean;
907 -- Returns True if A1 and A2 are (essentially) the same aspect. This is not
908 -- a simple equality test because e.g. Post and Postcondition are the same.
909 -- This is used for detecting duplicate aspects.
910
911 procedure Set_Aspect_Specifications (N : Node_Id; L : List_Id);
912 -- The node N must be in the class of declaration nodes that permit aspect
913 -- specifications and the Has_Aspects flag must be False on entry. L must
914 -- be a non-empty list of N_Aspect_Specification nodes. This procedure sets
915 -- the Has_Aspects flag to True, and makes an entry that can be retrieved
916 -- by a subsequent Aspect_Specifications call. It is an error to call this
917 -- procedure with a node that does not permit aspect specifications, or a
918 -- node that has its Has_Aspects flag set True on entry, or with L being an
919 -- empty list or No_List.
920
921 procedure Tree_Read;
922 -- Reads contents of Aspect_Specifications hash table from the tree file
923
924 procedure Tree_Write;
925 -- Writes contents of Aspect_Specifications hash table to the tree file
926
927 end Aspects;